Air cleaner



Feb. 21, 1933.

F. s. OREM.

AIR CLEAN R Filed May 28, 1931- W a e W J Patented Feb. 21, 1933 FREDERICK STRATTNEE- OREM, OF BALTIMORE, JNIARYLAND AIR CLEANER Application filed May 28,

.The invention relates to improvements in air cleaners, particularly for cleaning the air supplied to the carburetors of internal combustion engines. 7

An object of the invention is to provide a device eificfent at all speeds of the engine for cleaning the air of dust.

The invention aims to provide an efficient air cleaner which will function to eifectively remove all dust from the supplied air at all speeds, of the engine, but which will in no way retard or interfere with the tree flow of air from the atmosphere to the carburetor.

Another object is to provide an opening in the wall of one of the filtering units, the opening being of a shape such that, responsive to the pull of the carburetenthere will be a tendency to uniformity and equaldistribution of flow of the air and uniform application of the air to pass over or through the filtering material throughout the extent thereof.

Another object is to provide for direct passage of the cleaning air from the interior of the innermost filtering unit. to the air cleaner outlet leading to the carbureter without interposition of an impervious shell memher or baifie.

A further object is the provision of an air cleaner which requires no attention and which is free-from noise during operationand which muiiles the noise produced by the carbureter.

Other objects will appear from the accompanying description, claims, and drawing setting forth one desirable embodiment of the invention which consists of the features and combination of parts disclosed and particularly set forth in the claims.

Referring to the drawing, showing one embodiment of the invent on,

Figure 1 is a longitudinal sectional elevation of the air cleaner disposed in a horizontal position for connection to the carbureter or engine intake.

Fig. 2 is a section on line 22 of Fig. 1.

Fig. 3 is an end view of the eccentrically disposed outer tubular filter member, having an opening to receive a filter member of 1931. Serial No. 540,756.

smaller diameter which is concentric or coaxial with the outer casing.

Fig. 4 is an end view of the innermost filter member having an opening to be fitted over the end of the air outlet tube connected with the intake of the carbureter.

F ig. 5 is a bottom plan view of the filter member of Fig. 4 showing the slot or opening in the filter wall tapering toward the carbureter intake. 7 6

Fig. 6 is a fragmentary end View of the out-let tube C and its connection to the head of the air cleaner.

Fig. 7 is a detail.

In the drawing, A represents the cylindrical outer casing of my device which is shown in position with its axis horizontal. Owing to the location of the carburetor on some internal combustion engines, it is more convenient to use a horizontal type of air cleaner. However, I do not desire to limit my air cleaner to use in a horizontal position.

The outer casing A is closed at one end by an integral wall and is closed at the opposite end by a head orcap member 0, having an annular flange a encircling the tubular housing. The tubular housing portion of easing A is provided, preferably at its lower side, with a longitudinal opening or slot 0 providing an inlet for dust laden air.

The cap or head member a is also provided with a concentric flange (Z providing a central circular opening 6 through the head. Mounted in the circular opening 6 and secured to the head by any suitable means is a tube or cylinder C which is adapted to be connected with the intake of the carbureter and through which the air must pass in leaving the cleaner.

In the construction shown, the tube C is fastened in place in the head a by means of a cotter pin or bolt f passing through aligned holes 9 in the tube C and flange d of the head a.

The pin 7 passes through an eye h in the rod j, which rod extends through the cleaner from one end to the other and is secured on the outside of the closed end Z) of the casing A. by a nut 70 received on its threaded end Z.

For a generally similar construction, reference is made to my copending application, Serial Number 109,G26, filed November 25, 1929. The principal differences of the present application over said copending application are the elimination of the extension of the impervious shell or tube C through the cleaner, thus eliminating the baffle effect of this inner shell, and providing a direct and free flow of clean air from the inner filter unit to the air cleaner outlet opening provided by the tube C. The present invention also provides a tapered slot in the filter unit which contributes to uniformity in distribution of flow and application of the air against the filtering material.

Coaxial with the tube 0 is the inner tubular filter unit B. This filter unit may comprise a rectangular section of wire screening K covered with filter material and formed or rolled into substantially tubular shape, but with its opposed edges spaced apart to provide a longitudinal opening or slot in the filter as in my copending application 409,626, and retained in such position by retaining cap members M, N, placed over t 1e ends of the tubular filter. The wire screening K may, if desired, be made as shown by joining its edges to form a complete tube and subsequently cutting out a longitudinal slot of less extent than the screen which underlies the cap members M and N. The opposed edges of the slot R are overlapped by the filtering material, which is folded beneath the edges and fastened by clips R or the like.

The slot R in filter unit B is constructed of a tapered shape such that, responsive to the pull of the carbureter, there will be a tendency to uniformity of flow of air and of application of the air to the filtering material throughout its extent. The size of the tapered opening is calculated so that the fiow through the narrow end adjacent the inlet to the carbureter where the pull is greatest will be substantially the same as the flow through the other and wider portions of the slot B.

Fig. 4 shows the filter unit B provided with the retaining cap M at the outlet end of the casing, leaving an opening to receive the outlet tube C, which projects slightly inwardly of the inner face of the head a.

The other end of the filter B is provided with closed retainer cap N leaving an openin through which the tie rod extends. The filter is preferably disposed as shown with the tapered slot- R at its lower side.

The casing A and the filter B, together with the outlet C, are mutually coaxial and the annular spaces between them are of uniform size. The slots in the casing A and in the filter B are each downwardly disposed.

In the annular space between the casing A and filter B is disposed another tubular filter member D, the longitudinal axis of which is displaced with respect to the mutual axis of A, B, and C. This offset axis of tubular filter member D causes the eccentric arrangement shown in Figs. 1 and 2 in which the lower side of filter D is spaced upwardly away from the lower side of the casing A, and the upper side of filter D is spaced upwardly away from the upper side of filter B. This provides an outer eccentric or tapered passageway F, widest at its lower side at inlet opening 0 in casing A, and tapering upwardly on either side to its narrowmost portion at its upper side at slot 02/ in filter D. This also provides an inner eccentric or tapered passageway E, widest at its upper side at inlet slot at in filter D, and tapering downwardly on either side to its most restricted portion at its lower side at tapered slot R in filter B.

The filter D is constructed similarly to filter B of wire screen and filter material, but is provided with a slot 12. of uniform width.

I do not desire to limit the invention to the application of the tapered slot to only the innermost filter member. The retainin cap member 3 of filter D, as shown in Fig. 3, is provided with an opening to receive the filter B with its cap M fitting snugly in said opening. The retaining cap member N on the opposite end of filter D is closed except for the opening through which the tie rod extends. Cap member N of. filter D engages the inner face of head or closed end I) and the cap member N of filter B in turn engages the inner face of cap member N, as clearly shown in Fig. 1. The cap member M of filter D is preferably provided at its upper portion with a hole p to r ceive a retaining screw 1 passing through a registering hole in the head a, to secure the parts together in proper relative position circumferentially. Likewise, the cap member M of filter B is provided at its lower portion with an opening s to receive a screw 15 passing through the head a. I preferably provide a notch 10 in the forward edge of the casing A to cooperate with a dependent pin or screw 1) in the head a to secure the parts in proper circumferential relation.

In the operation of my device, the dust laden air enters the cleaner through opening 0 in the outer tubular casing A to eccentric annular passage F and passes through filter D to eccentric annular passage E. Some of the air will also pass through opening n to passage E, the filter D acting as a battle with respect to this particular portion of the air.

The air in passage E will then pass through filter B to its interior which is in direct uninterrupted and non-baffled communication with the outlet opening provided by the tube C connected with the inlet to the carbureter. Air will also pass through passage E to opening R to the inner space H, filter B acting as a battle as to this particular portion of the air. The cleaned air in space H passes directly and freely through the open end of tube C and to the carbureter.

The filter units D and B, each comprising the wire net supporting a povering of filtering material, function both as filters and also as bafiies so that there is no interference under any condition with the tree fiow of air from the atmosphere to the carbureter.

Casing A, filter B, and tube C are coaxial and concentric while D is eccentrically mounted with its axis ofiset which makes the inner and outer passages E and F eccentric or tapered, the object being to increase the velocity of air passing from opening 0 through passage F to opening a and from opening a through passage E to opening R.

Passages E and F each in effect comprise a pair of tapering passages having separate circuitous paths, each pair having the same inlet and outlet, and each passage being larger at its inlet and gradually tapering to its smallest portion at its outlet. By this construction the velocity of the air is increased as it passes from the wider portion of the passage to a narrow or restricted portion.

The resistance offered to the flow of air by reason of the tapered passages, while not sufficient to interfere with the free flow of air to the carbureter under any and all conditions, has a tendency to induce the air to pass directly through filters D and B instead of through said continuous tapered passages and openings, the air taking the path of least resistance.

lVhen the engine is running at high speed with the throttle wide open, the continuous tapered passageways will serve as an auxiliary passageway for the air, and the circuitous path traveled by the air baffled by the filters will ellectively clean the same.

The air which passes in opposite directions around the filtering units will meet with considerable force or impact at the opposite side which will cause a disturbance in the nature of a small whirlwind or hurricane effect, which will further serve to effectively rid the air of dust particles.

The unitary construction of the parts as shown in the drawing, and the simplicity of construction provides for ready assembling of the device.

Any number of filters could be added to this cleaner without departing from my invention and carrying out the principle exemplified by the structure herein shown and described as constituting one embodiment of my invention.

1 do not desire to limit the invention to the exact structure disclosed as it will be apparent that many modifications may be made therein within the scope of the invention.

I do not desire to limit the invention to the particular material of which the filters may be constructed. Any kind of filtering material may be used such as felt, flannel,

mineral wool or any porous material, including poro'us asbestos.

It is not desired to limit the invention to any particular number of eccentric passageways as it will be apparent that more may readily be provided by the suitable interposition of further eccentric or concentric filter units. 7

I claim:

1. In an air cleaner, a substantially tubular casing having an air inlet opening in its wall, a substantially tubular filter unit dis posed within the casing with its axis spaced from the axis of the casing and having a wall pervious to air and provided with an air passage at a point remote from the air inlet in the casing, the interior of said filter unit communicating with an air outlet in one end of the casing, said air outlet being substantially free at all sides to receive and discharge air from within said filter unit.

2. In an air cleaner, a. substantially tubular casing having an air inlet opening in its wall,

a substantially tubular filter unit disposed within the casing and having a wall pervious to air and provided with an air passage at a point remote from the air inlet in the casing, the interior of said filter unit communicating with an air outlet in the end of the casing, said air outlet being substantially free at all sides to receive and discharge air from within said filter unit.

3. In an air cleaner, a substantially tubular casing having an air inlet opening in its wall, a substantially tubular filter unit disposed within the casing and having a Wall pervious to air and provided with an air passage at a point remote from the air inlet in the casing, the space between the walls of said casing and filter unit being greater at the casing inlet opening and less at the air passage in the wall of the filter, the interior of said filter unit communicating with an air Outlet in the end of the casing, said air outlet being substantially free at all sides to receive and discharge air from within said filter unit.

4:. An air cleaner comprising a casing of substantially tubular form having substantially tubular filter members pervious to air nesting within the said casing in spaced relation, said casing having a lateral inlet opening, and said tubular filter members each having a lateral inlet opening, said lateral inlet openings being in substantial diametrical alignment and being disposed alternately and successively in the walls of said cas-' ing and of said tubular filter members on their opposite sides, and an air outlet through the end of the casing, said outlet communicating directly with the unoccupied interior of the innermost tubular filter member.

5. An air cleaner comprising a casing of substantially tubular form having substantially tubular filter members nesting within the said casing in spaced relation, said casing having a lateral inlet opening, and said tubular filter members each having a lateral inlet opening said lateral inlet openings being in substantial diametrical alignment and being disposed alternately and successively in the walls of said casing and of said tubular filter members on their opposite sides, and an air outlet through the end of the casing, said outlet communicating directly with the unoccupied interior of the innermost tubular filter member, one or more of the tubular casing and nested tubular filter members having its aXis ofliset or spaced from the axis of another.

6. A filter unit for an air cleaner for a carbureter, comprising a substantially tubular filter having a lateral inlet opening through its tubular wall, said opening comprising a slot extending longitudinally of said lter wall and tapering toward that end of the filter unit which is to be disposed adjacent the outlet for the air cleaner leading to the carbureter.

7. A filter unit according to claim 6 in which said tapered slot extends substantially throughout the length of said filter wall.

8. A filter unit according to claim 11 in which the ends of said slot are within the end edges of said filter material and said holding means comprises cap members with flanges overlying the ends of the filter material the ends of said slot substantially meeting the edges of the cap flanges.

9. A filter unit according to claim 11 in which the filter unit is provided at one end with an outlet opening, and in which said slot is tapered toward the end of the unit provided with the outlet opening.

10. A filter unit according to claim 11 in which said filter material comprises a wire net or the like and a covering of filtering fabric, said covering fabric at the slot being turned under the wire net and secured by clip fasteners.

11. A filter unit for an air cleaner comprising a sheet of filter material in substantially tubular form with its opposed edges meeting and a lateral inlet opening in its tubular wall in the form of a slot, the ends of said slot being within the end edges of said filter material, and means for holding the filter material in such condition, said means comprising cap members with flanges overlying the ends of the filter material.

In testimony whereof, I aflix my signature.

FREDERICK STRATTNER OREM. 

